Web Mapping Illustrated

Chapter 3. Converting and Viewing Maps

While presenting maps on the Web is fantastic, the data for those maps has to come from somewhere. You'll also want to have a toolkit for creating or modifying maps to fit your needs, especially if you're developing in an environment that isn't already GIS-oriented. This chapter introduces end-user applications for viewing and sharing data as well as low-level tools for data access and conversion.

While many other open source GIS and mapping tools exist, this chapter covers the small selection used throughout the remainder of this book. While many other excellent options exist, the sample of tools described here are robust enough for professional use. These free and open source GIS/mapping products are successfully used throughout industry, government, and academia.

For more general information and links to other tools, see the following reference web sites:

If you have the funds or already have the tools, you can, of course, use proprietary GIS software to create the data you'll be presenting with open source software. One of the best features of the open source tools is their ability to work with data created by proprietary applications and stored in proprietary formats.

Raster and Vector

The terms raster and vector are used throughout this chapter. They both refer to specific types of data. Raster data is organized as a matrix or grid that has rows and columns; each row/column intersection is a cell or pixel. Each cell has a value, for example, ...